<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			#set{
				width: 1000px;
				height: 600px;
				background-color: palevioletred;
				font-size: 24px;
			}
			/*#set div:first-of-type {
				width: 500px;
				margin: 120px 120px;
				height: 400px;
				background-image: url(img/a2.png);
				background-position: top;
				background-repeat: no-repeat;
				background-color:skyblue;
			}*/
			#set div:first-of-type span{
				width: 125px;
				height:125px;
				display: block;
				background-color:seagreen;
			}
		</style>
	</head>
	<body> 
		<section id="set">
			<div>第一个DIV
				<span>SPAN</span>
			</div>
			<br>
			<div>第二个DIV
				<span>第二个DIV里的SPAN</span>
			</div>
		</section>
	</body>
</html>
